Selvedge chain stitch machine



April 3 1963 R. FLACH ETAL SELVEDGE CHAIN STITCH MACHINE '5 SheetsSheet 1 Filed May 23, 1960 54/09/20 miuez 8 M, 67

FIG. 7

April 30, 1963 R. FLACH ETAL SELVEDGE CHAIN STITCH MACHINE 3 Sheets-Sheet 2 Filed May 25, 1960 E ABD Mil/.Efi

Anna/76 j April 30, 1963 R. FLACH ETAL SELVEDGE CHAIN STITCH MACHINE 3 SheetsSheet 3 Filed May 23, 1960 FIG. 7

3 w Mm A United States Patent ()fice 3,087,446 Patented Apr. 30, 1963 3,087,446 SELVEDGE CHAIN STITCH MACHINE Rolf Flach and Erhard Miiller, Kempten, Allgau, Germany, assignors to Xaver Fendt & (10., Allgau, Germany Filed May 23, 1960, Ser. No. 31,105 Claims priority, application Germany May 27, 1959 8 Claims. (Cl. 112203) The present invention relates to a selvedge chain stitch machine having either a straight or curved thread-carrying sewing needle cooperating with a looper, which may or may not carry a thread, and with a stitch finger.

Machines of this type are special sewing machines which are used for sewing the selvedges of cloth goods, and in which the goods are passed in a vertically suspended position along the stitch forming tools, this operation being usually carried out by means of a feeding mechanism which consists of two cooperating horizontal disks. The known machines of this tvpe have certain disadvantages which are especially apparent in the operation of the two cloth-feed cylinders and also in the operation of the cloth take-up roller. These feeding cylinders which have relatively large diameters often produce a stretching of the two edges of the cloth which results in wavy seams. Due to the short linear or point contact of the feed cylinders, it has so far been nelessary to provide a voluminous and interfering drive mechanism for the two feed cylinders for taking along the two selvedges of the cloth. However, even such a drive mechanism does not insure that the cloth will be properly taken along and guided, and consequently the seams may vary in height, especially at the beginning and end of each sewing operation. When this type of arrangement is applied, it is also necessary to draw the chaining or linking thread which connects the two pieces of cloth by hand at the end of each sewing operation and also at the beginning of each new operation since it will otherwise not be formed. This only leaves one hand free for. guiding the cloth. The same also applies for the operation of the cloth take-up roller which must be carried out by hand when two cloth edges are to be inserted and when adjustments in height have to be made.

The known machines of this type are equipped with a straight sewing needle which always requires a very accurate and ditficult adjustment relative to the two stitch forming tools if faulty stitches are to be prevented. The large stroke of the needle bars which is also required has a very unfavorable effect upon the quietness of the operation of the entire machine.

It is an object of the present invention to overcome these disadvantages and it is for this purpose proposed for selvedge chain stitch machines in which cloth feeding means which are rotating within a horizontal plane convey the cloth past the stitch forming place in a vertically suspended position, to design the two cooperating feeding means in the form of endless belts or the like. For taking along and guiding the edegs of two pieces of cloth which are to be connected, it is advisable according to the invention to provide two endless belts which are taken along by toothed rollerlike pulleys. Each of these belts is provided at the side facing toward the cloth and parallel thereto with teeth, transverse ribs or the like. The pulleys for supporting one belt are mounted in a fixed position, while the pulleys for supporting the other belt are to be mounted so as to be pivotable about an axis which extends vertically to the plane of the belts and also so as to be slidable in a direction transverse to the direction of movement of the cloth. It is further advisable to mount the rollerlike pulleys of the pivotable and slidable belt on a plate which, in turn, isvmounted on a supporting bracket which is held under spring tension relative to the housing of the machine. Also provided is a spring or the like between the supporting bracket and the pulley which is spaced from the place where the cloth is being fed, which spring presses the before-mentioned plate in the direction toward the other belt. It is further advisable to provide a guide rail for each belt, and to provide the guide rail which is associated with the pivotable and slidable belt with a larger bore which merges in the upward direction into an elongated slot, and to provide the other guide rail with a circular bore. The swivel axis of the pivotable and slidable belt is then to be disposed at a point between the two pulleys of this belt, and one of the two pulleys which are mounted in a fixed position is adapted to be driven, although it also is possible to drive each of the two belts by means of three pulleys.

It is further advisable although not absolutely necessary to use a curved sewing needle rather than a straight needle was customarily used in selvedge chain stitch inachines, and to operate the cloth take-up roller by foot. A curved sewing needle has the advantage that the thread of the sewing needle will be taken up properly and reliably, while the foot-operation of the cloth take-up roller has the advantage that the operator of the machine will always have both hands free for guiding the cloth.

In order to draw up the linking thread, it is further advisable to provide special means which are suitable for this purpose, such as knurled flanges, at the beginning of the twofeeding means, especially on the starting pulleys.

These objects, features, and advantages of the present invention will become more clearly apparent from the following detailed description thereof, particularly when the same is read with reference to the accompanying drawings, in which FIGURE 1 shows a top plan view of the cloth-guiding parts of a sewing machine according to the invention which is provided with two rollerlike pulleys for each of the two belts;

'FIGURE 2 shows a partial side view of the belt guiding pulleys which are facing in the direction opposite to the place of entry of the cloth;

FIGURE 3 shows a top plan view of the embodiment according to FIGURE 1 in the position of the associated parts at the time of the entry of the cloth;

FIGURE 4 shows a plan view similar to FIGURE 1 but of a modification of the invention in which each belt is associated with three pulleys and in which the bracket 13 is disposed at the side of these pulleys and belts opposite to that shown in FIGURE 1;

FIGURE 5 shows a plan view similar to FIGURE 3 of the embodiment according to FIGURE 4 at the time of the entry of the cloth;

FIGURE 6 shows a partial side view similar to FIG- URE 2 of the embodiment according to FIGURE 4;

while FIGURE 7 shows a perspective view of a sewing machine embodying applicants cloth-guiding means as shown in FIGURE 1.

Referring to the drawings and to FIGURES 1 to 3 and 4 to 6, respectively, an arm 1 which is rigidly secured to the machine housing 2 either supports two rollerlike guide pulleys 3a and 5a or three guide pulleys 3a, 4a, and 5a for guiding an endless belt 6 which is provided with transverse toothlike ribs 7. One of the two or three guide pulleys, for example, pulley 4a, may be driven by a shaft, not shown, mounted in housing 2 so that belt 6 and thus also the second belt 8 having transverse toothlike ribs 12 will be moved in the direction as shown by the arrows. may, for example, be bolted thereto and extends within Arm 1 further carries a guide rail 9 which a plane parallel to the plane in which belts 6 and 8 are located. Guide rail 9 contains a needle bore 10.

The pulleys which are used for guiding the second belt 8 are rotatably mounted on a supporting plate 11 which, in turn, is mounted on a bracket 13 so as to be pivotable about the vertical axis 4 shown in FIGURE 1 or the vertical axis of pulley 411 shown in FIGURE 4. Between supporting plate 11 and bracket 13 a spring 14 is provided which tends to pivot supporting plate 11 in a counterclockwise direction. Supporting plate 11 also. carries a guide rail 16 which is likewise provided with a needle bore 17. Bracket 13 is mounted on the machine housing 2 so as to be movable within a horizontal plane and it is acted upon by a spring 15 which tends to shift it in the direction toward housing 2. If no cloth is passed between the ribbed belts 6 and 8, spring 15 urges them toward and into interengagement with each other. If bracket 13 is shifted in the direction against the ac-. tionof spring 15, for example, by means of a foot lever or the like, supporting plate 11 will be pivoted in a counterclockwise direction because of the arrangement of spring 14 between plate 11 and bracket 13. The distance between guide pulleys 3a and 3b of the two ribbed belts will therefore be increased so that the edges 18 of the cloth which are to be sewed together will be inserted between the ribbed belts by the take-up roller, not shown, which is associated with the machine, whereupon bracket 13 will be returned to its original position. Spring 15 on bracket 13 then insures that belt 8 will press the cloth edges 18 and 19 against belt 6-. It is therefore not necessary also to provide special driving means for belt '8, as was required for the known feeding cylinders, since there is now a relatively large contact surface between the parts which effect the feeding movement, while previously the feeding cylinders only had a linear contact with each other and could therefore also exert only a linear engagement upon the cloth to be fed.

After the two cloth edges 18 and 19 have passed the sewing point at the sewing needle 20, a linking or chaining thread is formed which is drawn along by the cloth until it has passed out of the belts. It is thus possible to form the linking thread automatically at the beginning and end of each sewing operation since the linking thread which is formed at the sewing point takes over the function of drawing up the linking thread between the two flanges 21 and 22 of the pair of pulleys a and 5b so that the linking thread will be formed continuously at the sewing point. The flanges 21 and 22 function as. follows: When the endof a workpiece with the two cloth edges -18 and 19 has passed the point of sewing at the sewing needle 20, a chain is formed automatically if the end of the workpiece is under pulling stress becauseonly under these conditions will a loop be formed, a requirement for the chain. The pull exerted by the workpiece upon the chain will cease when the workpiece leaves the belt guide. In other words the formation of a chain will come to an end there unless other means come into play which will keep the chain under pulling stress. The interruption of the chain will cause not only an unde-. sirable knotting together of the two threads (sewing needle thread and catcher thread) 'but also an untidy beginning of the seam of each workpiece. Since the. chain is located at a height level determined by the juncture line of the two knurled flanges 21 and 22 of the bobbin pair 5a and '5b,the chain will be seized by these flanges as soon as the workpiece leaves the belt guide because the flange 22 is then pressed by the spring 15, byway of hook 13 and base plate 11, against flange 21.

The feedingof a new workpiece into the beltguide will also-not interrupt the chain. The two flanges will not sprea'd apart becausein this case spring 14 will come into action, with the base plate 11 swiveling at the same time about its axis 4. In this connection it will be noted that the species illustrated by FIGURES 1 to 3 shows theinsertion ot-the workpiece from right toleft, and the 1 special illustrated by FIGURES 4 to 6 the insertion from left to right.

As indicated in the drawing, particularly FIGURES 1 and 4, the parts 18 and 19 of the workpiece which are to be sewed together are inserted into the belts 6- and 8 in such manner that one set of their borders projects over the plane which is determined by the adjoining belt edges shown in FIGURES 2 and 6. When the two parts-now sewed togetherhave passed the point of sewing they are seized by the flanges 21 and 22 and are kept moving, even if the sewing needle 20 does not pierce the workpiece parts any longer, and the chain will be formed thereby.

Since the sewing needle 20 never emerges entirely out of the bore 10, it can also not shift laterally if cloth bulges pass between the belts. The possibility that the stitch forming tools might pass into each other is thus also avoided.

Although not particularly shown in the drawings, it may be advisable to guide the supporting bracket 13 by a pair of pins, bolts, or the like relative to the machine housing in order to prevent the bracket from swiveling.

Although our invention has been illustrated and described with reference to the preferred embodiments thereof, We wish to have it understood that it is in no way limited to the details of such embodiments, but is capable of numerous modifications within the scope of the appended claims.

Having thus f-ully disclosed our invention, what we claim is:

1. In a selvedge chain stitch sewing machine having cloth feeding means rotatable within a horizontal plane for moving the cloth in a vertically suspended position past the stitch forming place, in which said feeding means consist of at least two endless belts operatively associated with and partly facing toward each other, a first set of pulleys for guiding one of said belts, a second set of pulleys for guiding another of said belts, fixed supporting means for said first set of pulleys, supporting means for said second set of pulleys including a plate member on which said second set of pulleys are rotatably mounted, a bracket member slidably mounted on said machine for movement parallel to said horizontal plane, and pivot means connecting said plate member to said bracket member, the axis of said pivot means being vert1ca 2. In a selvedge chain stitch sewing machine having cloth-feeding means rotatable within a horizontal plane for moving the cloth in a vertically suspended position past the stitch-forming place, in which said feeding means consist of at least two endless belts operatively associated with and partly facing toward each other, said machine further having a sewing needle operatively associated with a looper and a stitch finger, in which for taking along and guiding the edges of two cloth parts to be connected, each of said endless belts is provided with tooth-like ribs facing toward the cloth and extend ing substantially parallel thereto, and roller-like pulleys having teeth for guiding said belts, the pulleys for guiding one of said belts being rotatably mounted in a fixed position and the pulleys for guiding the other belt being mounted so as to be pivotable about an axis extending vertically to the plane of said belts and also so as to be slidable in a direction transverse to the plane of movement of the cloth.

3. In a selvedge chain stitch sewing machine as defined in claim 2 in which a supporting member is provided for rotatably mounting said pulleys of said pivotable and slidable belt, a supporting bracket slidably mounted on said machine, said supporting member being p-ivotably mounted on said bracket, spring means acting upon said bracket to urge said supporting member with said pivotable and slidable belt thereon in the direction toward the other belt, and spring means for urging the side of said supporting member carrying the out-going pulley thereon in the direction toward the other belt.

4. In a selvedge chain stitch sewing machine as defined in claim 2, in which a guide rail is provided for each belt, each of said guide rails having a bore for the movement of the sewing needle, the bore in at least one of said guide rails merging in the upward direction into an elongated slot.

5. In a selvedge chain stitch sewing machine as defined in claim 2, in which three rollerlike pulleys are provided in a triangular formation for guiding each of said belts, the axis of one of the pulleys of the pivotable and sl-idable belt spaced from the associated pulleys facing directly toward the other belt forming the pivotal axis of said belt, and means for driving one of the pulleys which are mounted in said fixed position.

6. In a selvedge chain stitch sewing machine as defined in claim 2, in which at least said pulleys at the entry side of the cloth are provided with means for drawing along the linking stitches.

7. In a selvedge chain stitch sewing machine, the combination according to claim 2, wherein two of said pulleys are provided with mutually adjacent flanges, said flanges and said sewing needle being disposed in a common plane, said plane being substantially perpendicular to the direction of movement of said cloth.

8. In a selvedge chain stitch sewing machine having cloth-feeding means rotatable within a horizontal plane for moving the cloth in a vertically suspended position past the stitch forming place, in which said feeding means consist of at least two endless belts operatively associated with and partly facing toward each other, said feed ing means including pulleys for driving said belts, two of said pulleys having flange means thereon disposed in a plane substantially perpendicular to the direction of movement of said cloth, said sewing machine further comprising a needle at said stitch-forming place, said needle being disposed in said plane.

References Cited in the file of this patent UNITED STATES PATENTS 1,403,874 Seymour Jan. 17, 1922 2,060,897 Richardson et al Nov. 17, 1936 2,106,536 Rubel et a1 Jan. 25, 1938 2,164,501 Cundall et al. July 4, 1939 2,199,270 Roselius et al. Apr. 30, 1940 FOREIGN PATENTS 508,129 Germany Sept. 27, 1930 

1. IN A SELVEDGE CHAIN STITCH SEWING MACHINE HAVING CLOTH FEEDING MEANS ROTATABLE WITHIN A HORIZONTAL PLANE FOR MOVING THE CLOTH IN A VERTICALLY SUSPENDED POSITION PAST THE STITCH FORMING PLACE, IN WHICH SAID FEEDING MEANS CONSIST OF AT LEAST TWO ENDLESS BELTS OPERATIVELY ASSOCIATED WITH AND PARTLY FACING TOWARD EACH OTHER, A FIRST SET OF PULLEYS FOR GUIDING ONE OF SAID BELTS, A SECOND SET OF PULLEYS FOR GUIDING ANOTHER OF SAID BELTS, FIXED SUPPORTING MEANS FOR SAID FIRST SET OF PULLEYS, SUPPORTING MEANS FOR SAID SECOND SET OF PULLEYS INCLUDING A PLATE MEMBER ON WHICH SAID SECOND SET OF PULLEYS ARE ROTATABLY MOUNTED, A BRACKET MEMBER SLIDABLY MOUNTED ON SAID MACHINE FOR MOVEMENT PARALLEL TO SAID HORIZONTAL PLANE, AND PIVOT MEANS CONNECTING SAID PLATE MEMBER TO SAID BRACKET MEMBER, THE AXIS OF SAID PIVOT MEANS BEING VERTICAL. 